On the Ytterbium Valence and the Physical Properties in Selected Intermetallic Phases.

The present review summarizes important aspects of the crystal chemistry of ytterbium-based intermetallic compounds along with a selection of their outstanding physical properties. These originate in many cases from the ytterbium valence. Different valence states are possible here, divalent (4f14), intermediate-valent, or trivalent (4f13) ytterbium, resulting in simple diamagnetic, Pauli or Curie-Weiss paramagnetic, or valence fluctuating behavior. Especially, some of the Yb3+ intermetallics have gained deep interest due to their Kondo or heavy Fermion ground states. We have summarized their property investigations using magnetic and transport measurements, specific heat data, NMR, ESR, and Mössbauer spectroscopy, elastic and inelastic neutron scattering, and XAS data as well as detailed thermoelectric measurements.

K3Mo2O5.6F3.4 and K3V2O3.3F5.7 - exploring transition metal cation valence and anion distribution in oxyfluorides.

Oxyfluorides come in many different structures and are highly adaptable in composition, not least because of their mixed-anionic nature. Slight changes, unless specifically looked for, can easily go unnoticed. In this paper, we present two oxyfluorides, K3Mo2O5.6F3.4 and K3V2O3.3F5.7, synthesized under high-pressure/high-temperature conditions, and demonstrate the importance of careful analysis of composition, oxidation state and O/F anion distribution for an accurate description of oxyfluorides. Their crystal structures were determined by single-crystal X-ray diffraction and the transition metal cation valences analyzed by X-ray photoelectron spectroscopy (XPS). The O/F anion ratio was calculated using the principle of charge neutrality and the local distribution within the crystallographic framework was studied using bond valence (BV) and charge distribution (CHARDI) calculations. Madelung Part of Lattice Energy (MAPLE) calculations and magnetic measurements provide insight into phase stability and corroborate the mixed-valent nature of the compounds.

Experimental and computational study of the exchange interaction between the V(III) centers in the vanadium-cyclal dimer.

[V2(HCyclal)2] is prepared by controlled oxidation of vanadium nanoparticles at 50 °C in toluene. The V(0) nanoparticles are synthesized in THF by reduction of VCl3 with lithium naphthalenide. They exhibit very small particle sizes of 1.2 ± 0.2 nm and a high reactivity (e.g. with air or water). By reaction of V(0) nanoparticles with the azacrown ether H4Cyclal, [V2(HCyclal)2] is obtained with deep green crystals and high yield. The title compound exhibits a V(III) dimer (V⋯V: 304.1(1) pm) with two deprotonated [HCyclal]3- ligands as anions. V(0) nanoparticles as well as the sole coordination of V(III) by a crown ether as the ligand and nitrogen as sole coordinating atom are shown for the first time. Magnetic measurements and computational results point to antiferromagnetic coupling within the V(III) couple, establishing an antiferromagnetic spin S = 1 dimer with the magnetic susceptibility determined by the thermal population of the total spin ranging from ST = 0 to ST = 2.

Salt-flux growth of HoCuMg4 single crystals.

Polycrystalline samples of the magnesium-rich intermetallic compounds RECuMg4 (RE = Dy, Ho, Er, Tm) were synthesized by reaction of the elements in sealed tantalum ampoules heated in a high-frequency induction furnace. Phase purity of the RECuMg4 phases was ascertained by powder X-ray diffraction patterns. Well-shaped single crystals of HoCuMg4 could be grown in a NaCl/KCl salt flux and the crystal structure was refined from single crystal X-ray diffraction data: TbCuMg4 structure-type, space group Cmmm, a = 1361.4(2), b = 2039.3(4), c = 384.62(6) pm. The crystal structure of the RECuMg4 phases can be understood as a complex intergrowth variant of CsCl and AlB2 related slabs. The remarkable crystal chemical motif concerns the orthorhombically distorted bcc-like magnesium cubes with Mg-Mg distances ranging from 306 to 334 pm. At high temperatures DyCuMg4 and ErCuMg4 are Curie-Weiss paramagnets with paramagnetic Curie-Weiss temperatures of -15 K and -2 K for RE = Dy and Er, respectively. The effective magnetic moments, 10.66µB for RE = Dy and 9.65µB for RE = Er prove stable trivalent ground states for the rare earth cations. Magnetic susceptibility and heat capacity measurements reveal long-range antiferromagnetic ordering at low temperatures (<21 K). Whereas DyCuMg4 exhibits two subsequent antiferromagnetic transitions at TN = 21 and 7.9 K which successively remove half of the entropy of a doublet crystal field ground state of Dy, ErCuMg4 shows a single, possibly broadened, antiferromagnetic transition at 8.6 K. The successive antiferromagnetic transitions are discussed with respect to magnetic frustration in the tetrameric units present in the crystal structure.

bcc superstructures: RE2RuIn with RE = Sc, Y, Dy-Tm and Lu.

The rare earth-rich intermetallic phases RE2RuIn with RE = Sc, Y, Dy-Tm and Lu were synthesized by reactions of the elements in sealed tantalum ampoules in an induction furnace. The samples were characterized through Guinier powder patterns and the structures of Sc2RuIn and Er2RuIn were refined from single crystal X-ray diffraction data. The indides crystallize with the Pt2ZnCd type space group P4/mmm. The RE2RuIn phases are superstructures of the bcc packing and can be explained as intergrowth variants of tetragonally distorted, CsCl derived slabs of compositions RERu and REIn. Chemical bonding is discussed for Sc2RuIn and Sc2RuMg in comparison with the binaries ScRu, ScMg and ScIn. The Ru/Mg respectively Ru/In ordering leads to an increase of Sc-Sc bonding for the slab with the shorter Sc-Sc distances, while the Sc-Ru bond strength values remain similar. The strongest bonding interactions occur within the magnesium and indium square nets. Magnetic susceptibility measurements reveal Pauli paramagnetism for Lu2RuIn while Dy2RuIn, Ho2RuIn, Er2RuIn and Tm2RuIn are Curie-Weiss paramagnets. Antiferromagnetic ordering occurs at 13.1, 5.3 and 2.9 K for Dy2RuIn, Er2RuIn and Tm2RuIn, respectively. Dy2RuIn and Er2RuIn show metamagnetic transitions at critical fields of 4.6 and 3.2 T.

Follow-up of men with a PI-RADS 4/5 lesion after negative MRI/Ultrasound fusion biopsy.

Magnetic resonance imaging/Ultrasound (MRI/US) fusion targeted biopsy (TB) in combination with a systematic biopsy (SB) improves cancer detection but limited data is available how to manage patients with a Prostate Imaging-Reporting and Data System (PI-RADS) ≥ 4 lesion and a negative biopsy. We evaluate the real-world management and the rate of clinically significant Prostate Cancer (csPCa) during follow-up. 1546 patients with a multi-parametric MRI (mpMRI) and a PI-RADS ≥ 3 who underwent SB and TB between January 2012 and May 2017 were retrospectively analyzed. 222 men with a PI-RADS ≥ 4 and a negative biopsy were included until 2019. For 177/222 (80%) complete follow-up data was obtained. 66/84 (78%) had an initial PI-RADS 4 and 18 (22%) a PI-RADS 5 lesion. 48% (84/177) received a repeat mpMRI; in the follow-up mpMRI, 39/84 (46%) lesions were downgraded to PI-RADS 2 and 11 (13%) to PI-RADS 3; three cases were upgraded and 28 lesions remained consistent. 18% (32/177) men underwent repeated TB and csPCa was detected in 44% (14/32). Our study presents real world data on the management of men with a negative TB biopsy. Men with a positive mpMRI and lesions with high suspicion (PI-RADS4/5) and a negative targeted biopsy should be critically reviewed and considered for repeat biopsy or strict surveillance. The optimal clinical risk assessment remains to be further evaluated.

Global experience and progress in GreenLight-XPS 180-Watt photoselective vaporization of the prostate.

PURPOSE: To evaluate changes in global perioperative data of GreenLight-XPS 180-Watt photo-selective vaporization of the prostate (GL-XPS) of the Global Greenlight Group (GGG) database. METHODS: 3441 men, who underwent GL-XPS for symptomatic BPH between 2011 and 2019 at seven high volume international centers, were included. Primary outcome measurements were operative time (OT; min), effective laser time (LT; min of OT), as well as intraoperative and postoperative adverse events (AEs), all analyzed by year of surgery (2011-2019) and prostate volume (PV) group (< 80 ml vs. 80-150 ml vs. > 150 ml). RESULTS: The median age was 70 years (interquartile range 64-77), the median PV was 64 ml (IQR 47-90). The OT and LT slightly increased but stayed highly efficient all in all. Median OT was 60 min (IQR 45-83) and LT was 33 min (IQR 23-46). Median energy use was 253 kJ (IQR 170-375) with an energy density of 3.94 kJ/ml (IQR 2.94-5.02). The relative probability of perioperative AEs decreased by 17% each year (p < 0.001). The relative probability of perioperative transfusion dropped significantly from 2% in 2011 to 0% in 2019 (p = 0.007). The early postoperative complications (within 30 days after surgery) decreased significantly from 48.8% (n = 106) in 2011 to 24.7% (n = 20) in 2019 (p > 0.001). CONCLUSION: These findings from the GGG demonstrate significant improvement secondary to growing experience with GL-XPS between 2011 and 2019 in intraoperative AEs, including transfusions, and postoperative AEs. While staying highly efficient in OT and LT of GL-XPS within a 9-year period of experience.

Global Greenlight Group: largest international Greenlight experience for benign prostatic hyperplasia to assess efficacy and safety.

INTRODUCTION: Greenlight photo-selective vaporization of the prostate (GL-PVP) has gained international acceptance as a safe and effective alternative procedure for the treatment of benign prostatic hyperplasia (BPH), especially in anticoagulated men. This descriptive analysis aims to characterize the current state of GL-PVP, pooling data from international centers. METHODS: Data from 3627 patients who underwent GL-PVP with the XPS-180 W system in seven international centers performed by eight expert surgeons between 2011 and 2019 were retrospectively analyzed. Demographic, perioperative, and postoperative data were collected, including IPSS, QoL, Qmax, PVR, and PSA, and complications. RESULTS: At baseline, median age, prostate volume, PSA, and IPSS were 70 years (interquartile range 64-77), 64 (47-90), 3.1 ng/mL (1.8-6), and 22 (19-27), respectively. Median lasing and operative time were 34 (23-48) and 62 min (46-85), respectively. Median energy use was 250.0 kJ (168.4-367.9), with 92.6% of procedures being completed with one laser fiber. In 60.1% of cases, catheter was removed on postoperative day 1 with median length of 2 days. All-cause mortality within 30 days was 0.3%. Median PSA reduction at 3 months and 60 months compared to baseline was 43.9 and 46.4%, respectively (p < 0.001). All functional outcomes (IPSS, QoL, Qmax, and PVR) were significantly improved across study period when compared to baseline (p < 0.001). For those men with longer follow-up available, the observed surgical BPH retreatment rate was 1.5% CONCLUSION: Using the largest multi-user, international database of GL-PVP, Greenlight XPS laser treatment in experienced hands is a safe, effective, and durable BPH treatment option.

Outcome of Photoselective Vaporization of the Prostate with the GreenLight-XPS 180 Watt System Compared to Transurethral Resection of the Prostate.

The aim of this paper was to compare the perioperative and postoperative results of photoselective vaporization of the prostate with the GreenLight-XPS 180 Watt System (PVP) and transurethral resection of the prostate (TURP). This retrospective study included 140 men who underwent PVP and 114 men who underwent TURP for symptomatic benign prostate enlargement (BPE) between June 2010 and February 2015. The primary outcome measures were the patient reported outcome, operative results, International Prostate Symptom Score-Quality of Life (IPSS-QoL), complication rates, catheterization time, and length of hospital stay. The median follow-up times were 27 months (range 14-44) for the PVP group and 36 months (range 25-47) for the TURP group. The patient characteristics were well balanced in both groups with a median age of 71 years (PVP group) vs. 70 years (TURP group) and a comparable prostate volume (median 50 mL in the PVP group vs. 45 mL in the TURP group). The IPSS-QoL was significantly higher in the PVP group than in the TURP group (median 22 + 4; range 16-27 + 3-5 vs. median 19 + 3; range 15-23 + 3-4; p = 0.02). Men undergoing PVP were more likely to be on anticoagulants (PVP group n = 23; 16% vs. TURP group n = 2; 2%, p < 0.001). The median operation time (OT; min) for both procedures was comparable with 68 min (PVP group; range 53-91) vs. 67 min (TURP group; range 46-85). The rate of severe intraoperative bleeding was significantly lower in the PVP group than in the TURP group (n = 7; 5% vs. n = 16; 14%; p = 0.01). The postoperative catheterization time and length of hospital stay was significantly lower in the PVP group (median 1-2 days; range 1-4) vs. the TURP group (median 2-4 days; range 2-5; both p < 0.001). Complication rates (Clavien-Dindo classification ≥III) based on the follow-up data showed no statistically significant difference between the PVP group and the TURP group (n = 6; 4% vs. n = 6; 5%; p = 0.28). The IPSS on follow-up showed an equivalent reduction in symptoms for both treatment modalities (IPSS-QoL of 5 + 1; range 2-11 + 0-2 for both). There were no differences concerning urge (PVP group n = 3; 2% vs. TURP group n = 3; 3%; p = 0.90) and men were similarly satisfied with the postoperative outcome (PVP group 92% vs. TURP group 87%; p = 0.43). The PVP group was associated with a shorter hospitalization time and showed a reduced risk of bleeding, despite patients remaining on anticoagulants, without increasing the overall operative time. There was no difference in the patient reported outcome for both procedures.

Perioperative Changes and Progress in Photoselective Vaporization of the Prostate with GreenLight XPS 180 W System: A Single Center Experience.

PURPOSE: The study aimed to evaluate progression of GreenLight-XPS 180 W photoselective vaporization of the prostate (GL-XPS) with respect to effectiveness, efficacy, and safety over time at a tertiary referral high volume center. METHODS: The retrospective study included 375 men who underwent GL-XPS for symptomatic benign prostate obstruction (BPO) between June 2010 and February 2015. Primary outcome measurements were operation time (OT; min) and effective laser time (LT; min of OT) analyzed with regard to prostatic volume (PV; mL) (group 1 <40 mL up to 4 >80 mL in 20 mL steps) and the year of surgery (2010-2015). RESULTS: The median age was 72 years (range 64-79), the median PV was 58 mL (range 33-98) and the median PV increased from 42 mL in 2012 to 80 mL in 2015. The OT and LT clearly correlated with the PV, being doubled for glands of median 95 mL compared to median 30 mL while the applied laser energy per LT likewise steadily increased. Overall, both OT and LT could be significantly reduced each year by 37% (OT; p < 0.05) and 36% (LT; p < 0.05) within 5 years. The hospital stay (days) and catheterization time (days) remained constant, without any changes over time. The overall complication rate (Clavien-Dindo >2) ranged from 36 to 15% between 2010 and 2015. The pre (median 22 + 4) and postoperative International Prostate Symptom Score-Quality of Life (median 5 + 1) showed a sufficient reduction in symptomatic BPO. CONCLUSION: GL-XPS is a safe and effective surgical method for symptomatic BPO. Our single center experience showed a significant improvement of both OT and effective LT within 5 years whilst maintaining stable low complication rate and high patient satisfaction.

Peripheral nerve perfusion by dynamic contrast-enhanced magnetic resonance imaging: demonstration of feasibility.

PURPOSE: The aim of this study was to establish dynamic contrast-enhanced perfusion in peripheral nerves for determination of blood-nerve permeability (K) and nerve blood volume (NBV) in peripheral neuropathies as compared with healthy controls. METHODS: The study was approved by the institutional ethics committee, and written informed consent was obtained from all participants. Forty-three controls (24 women, 19 men; age, 48.7 ± 17.5 years) and 59 patients with peripheral neuropathy (28 women, 31 men; age, 52.7 ± 12.4 years) were examined by a standard protocol including a T1-weighted dynamic contrast-enhanced sequence (time of repetition/time of echo, 4.91/1.64; 10 slices; resolution 0.8 × 0.6 × 3.0 mm3). Time - signal intensity analysis was performed by normalizing to pre-bolus arrival and calculating the mean contrast uptake (MCU) for each patient. Further analyses were performed by customized software to calculate K trans and NBV. Statistical analysis included 2-sided Student's t tests of controls versus patients, receiver operating characteristic analysis, and subgroup analysis of patients according to etiologies of neuropathy. RESULTS: Time-signal intensity analysis showed significantly increased contrast uptake in patients as compared with controls (MCU, 1.29 ± 0.15 vs 1.18 ± 0.08; P < 0.001). This was caused mainly by an increase in K trans (0.046 ± 0.025 vs 0.026 ± 0.016 min(-1); P < 0.001) and less by an increase in NBV (3.9 ± 2.6 vs 3.0 ± 1.9 mL/100 mL; P = 0.12). This trend was true for all etiologies except entrapment neuropathies. Excluding these, receiver operating characteristic analysis found an area under the curve of 0.78 (95% confidence interval, 0.69-0.89) for MCU and 0.77 (95% confidence interval, 0.65-0.90) for K to discriminate neuropathy from control. CONCLUSIONS: Dynamic contrast-enhanced perfusion is a feasible technique to assess K trans and NBV in peripheral nerves and may be used in future investigations on peripheral neuropathies.